Mobile devices have long had the ability to track their own location relative to the surface of the Earth through receipt and analysis of wireless signals from multiple global positioning system (GPS) or global navigation satellite system (GNSS) satellites. Thus, users of such computing devices, whether carried on their persons or installed within vehicles, have long been able to view a visual presentation of where they are on the surface of the Earth at any given moment. Further, beyond simply presenting location information such as a current set of coordinates, mobile devices have long incorporated location applications or clients (hereinafter clients) to make use of such location information in providing other services (for example, presenting weather predictions for a current location; presenting locations of shops or gas stations, along with their prices, etc., near a current position; presenting nearby realtor listings; and the like).
More recently, mobile devices provide the ability to track their own location relative to an interior of a venue (e.g., an interior of a mall, a store, an airport terminal, etc.) with a finer location accuracy level than possible using signals emanating from satellites, which may also not be able to penetrate portions of such structures to reach their interiors. This is typically done by receiving and analyzing wireless signals emanating from wireless network access points (APs) forming a location network within such a venue. Further, such mobile devices have recently come to incorporate location clients to cooperate with location services provided by such a location network to guide users to locations of particular items of interest within a venue, such as products available for purchase, new products and/or products for which promotions are offered within that venue.
Such location clients rely on a location provider of a mobile device that has been configured to interact with such location network providing such location services within a venue to determine a current location of the mobile device relative to an indoor map of rooms, hallways, aisles, shelves, kiosks, information desks, restrooms, and the like. The location provider then provides the current location to a location client associated with the indoor map of the venue and able to correlate items of interest to the locations at which those items of interest are offered within that venue. Such correlations are then used to guide a user to items of interest and/or to present promotions (e.g., discounts) associated with those items.
Indoor maps are very client dependent, as it is very difficult to snap the indoor map to absolute worldwide coordinates, and therefore, most of the indoor maps that are available are using local coordinates of an AP of the venue. When the AP location data and client mapping data come from different sources, significant error is often introduced, reducing the ability to provide high-level accuracy of the indoor location (for example, of less than 1 meter resolution).
Further, positioning technologies typically require the availability of accurate locations of APs or other fixed location devices in order to calculate and determine a devices location. However, it is highly complicated to measure a location of a fixed location device with high accuracy (for example of less than 50 cm) and therefore, many location databases are inaccurate or simply don't exist.
It is desirable to enable more accurate indoor location determination and reduce the potential representation error introduced by using AP location information and mapping information from different sources.